<s>
Asynchronous	B-General_Concept
reprojection	I-General_Concept
is	O
a	O
class	O
of	O
computer	O
graphics	O
technologies	O
aimed	O
ensuring	O
a	O
virtual	B-Device
reality	I-Device
headset	I-Device
's	O
responsiveness	O
to	O
user	O
motion	O
even	O
when	O
the	O
GPU	B-Architecture
is	O
n't	O
able	O
to	O
keep	O
up	O
with	O
the	O
headset	O
's	O
target	O
frame	O
rate	O
.	O
</s>
<s>
Reprojection	B-General_Concept
involves	O
the	O
headset	O
's	O
driver	O
taking	O
one	O
or	O
multiple	O
previously	O
rendered	O
frames	O
and	O
using	O
newer	O
motion	O
information	O
from	O
the	O
headset	O
's	O
sensors	O
to	O
extrapolate	O
(	O
often	O
referred	O
to	O
as	O
"	O
reprojecting	O
"	O
or	O
"	O
warping	O
"	O
)	O
the	O
previous	O
frame	O
into	O
a	O
prediction	O
of	O
what	O
a	O
normally	O
rendered	O
frame	O
would	O
look	O
like	O
.	O
</s>
<s>
Basic	O
versions	O
of	O
the	O
technique	O
are	O
referred	O
to	O
as	O
by	O
Google	B-Application
and	O
Valve	O
,	O
while	O
Oculus	B-Application
has	O
two	O
implementations	O
,	O
called	O
and	O
.	O
</s>
<s>
Asynchronous	B-General_Concept
timewarp	I-General_Concept
uses	O
the	O
headset	O
's	O
rotational	O
data	O
to	O
extrapolate	O
a	O
new	O
rendered	O
frame	O
based	O
on	O
the	O
last	O
frame	O
it	O
received	O
.	O
</s>
<s>
Asynchronous	B-General_Concept
spacewarp	I-General_Concept
additionally	O
uses	O
depth	O
information	O
to	O
help	O
compensate	O
for	O
perspective	O
and	O
other	O
geometric	O
changes	O
.	O
</s>
<s>
Valve	O
's	O
early	O
version	O
called	O
interleaved	B-General_Concept
reprojection	I-General_Concept
would	O
make	O
the	O
application	O
run	O
at	O
half	O
frame	O
rate	O
and	O
reproject	O
every	O
other	O
frame	O
.	O
</s>
<s>
A	O
later	O
variant	O
by	O
Valve	O
is	O
SteamVR	O
Motion	O
Smoothing	O
,	O
which	O
builds	O
upon	O
regular	O
asynchronous	B-General_Concept
reprojection	I-General_Concept
in	O
being	O
able	O
to	O
reproject	O
two	O
frames	O
instead	O
of	O
one	O
.	O
</s>
